Dec. 5, 2007 -- Being overweight or obese as a child increases the risk of heart disease in adulthood, a new study suggests.
Children who are overweight are more likely to be diagnosed with coronary heart disease as adults compared with their skinnier counterparts, researchers from Denmark report in a study to be published in the New England Journal of Medicine.
The finding could be especially relevant for the United States, where growing numbers of obese children have medical experts worried about future health consequences -- and it could amplify calls for families, communities and governments to take action.
"A small increase in body weight substantially increases heart disease later in life," says Dr. David Ludwig, an associate professor of pediatrics at the Harvard Medical School, who wrote an accompanying editorial to the study.
"If childhood obesity markedly increases heart disease risks, we are looking at a huge public health problem," he says.
Researchers followed 277,000 Danish school children and found that overweight boys between the ages of 7 and 13, as well as overweight girls between the ages of 9 and 13, had an increased risk of both developing heart disease and dying from it as adults.
The older the children are, the higher the chance for later heart risk, the researchers also found. So, for example, a boy who was heavier than his peers at age 7 had a 5 percent increased risk for later heart disease, but a boy who was heavier than his peers at age 13 had a 17 percent greater risk.
"The study seems to underscore what we knew tends to happen in adults -- obesity increases your risk for heart disease," says Keith-Thomas Ayoob, associate professor of pediatrics at the Albert Einstein College of Medicine in New York.
"Children who have been obese for much of their childhood will enter adulthood with chronic health problems that will only continue if their BMI remains high."
Findings May Carry Even More Weight in U.S.
However, what U.S. experts find most concerning is that the fattest Danish boys were barely overweight according to this country's standards, which means that obese U.S. children could be at an even greater risk for heart disease.
"According to the study, the boy in the heaviest weight range had a 33 percent higher risk of developing heart disease," says Ludwig. "That is really disturbing. Boys in the heaviest weight category barely make it out of the normal weight range in the U.S., which means there is an even greater risk for the millions of obese children in the U.S."
Experts also warn that if left unchecked, childhood obesity and a sedentary lifestyle may undo advancements that have been made in heart disease prevention and survival.
"Major strides have been made in decreasing cardiovascular disease mortality in last few decades," says Dr. JoAnn Manson, a professor of medicine at the Harvard Medical School.
"The trends of increasing obesity in children and adolescents threaten to reverse the progress we have made. I think that a call to action is needed or we may be looking at a reversal of many of these gains."
The Heart of the Problem
Coronary heart disease), which is caused by the buildup of plaque in the arteries, results in restricted blood flow to the heart and can cause chest pain, heart attacks, and even heart failure. It is already the leading cause of death in the United States -- and its prevalence isn't likely to decrease anytime soon.
In fact, a related study, also to be published in NEJM, reports that if the number of overweight children continues to increase at current rates, there will be 100,000 additional cases of heart disease by 2035 that can be attributed to childhood obesity.
"Although projections 25 or more years into the future must be interpreted with great caution, currently available data and trends suggest that overweight among adolescents can be projected to cause substantial increases in the rate and the effect of CHD among future young and middle-aged adults," authors from University of California at San Francisco write in the paper.
Not only will childhood obesity take its toll on the heart, but it will also cause a number of other future health problems. Ludwig says that diabetes, liver damage and sleep apnea are likely to increase as well.
"Preliminary data ... suggest that adolescents with type 2 diabetes will be at high risk for limb amputation, kidney failure requiring dialysis and premature death," Ludwig writes in his editorial. "Fatty liver will progress ... until irreversible organ damage has occurred."
Dr. Meir Stampfer, professor of medicine at the Harvard Medical School, agrees that there are many additional health problems that will arise unless kids start losing weight.
"There are lots of other consequences of obesity in adult life including arthritis -- it's tough on the joints to carry all the extra weight -- diabetes, cancer, stroke, asthma, accidents, and list goes on," he says.
And because childhood obesity is linked to so many future health consequences, it can significantly reduce the lifespans. Ludwig and his colleagues estimate that in 2050 childhood obesity may shorten life expectancy in the United States by two to five years -- "an effect equal to that of all cancers combined," they say.
Addressing the Problem
The future burden on CHD might overwhelm both the health system and the economy unless certain steps are taken.
"It's a health crisis and could also be an economic crisis," says Ayoob. "The cost to our overburdened health system is unimaginable, but it doesn't have to be this way. This is fixable, but it takes a partnership of the community, the government and especially our parents to make it change."
The partnership Ayoob refers to begins at home.
"Individual parents need to really get involved here," he says. "Cut screen time to two hours a day or less. Eat with your kids -- meals that you cook at home. Make it a priority. Nothing will change otherwise."
Outside the home, schools and communities need to be involved. Experts recommend eliminating vending machines from school cafeterias and building safer playgrounds and sidewalks so kids can spend more time running around outside and less time in front of the television.
"There needs to be more physical activity in schools," says Manson. "I think that increasing physical activity is a major component to achieving and maintaining a healthy weight that is often overlooked."
And finally, experts say, the government and industry also have a responsibility. Health policy experts recommend changes in legislation which could make nutritious food cheaper and control the marketing of unhealthy foods.
"These studies are a wake-up call," says Manson. "We need to take this epidemic of overweight children very seriously. Obesity and sedentary lifestyle are independent factors of cardiovascular disease mortality, and the problem has to be approached by both increasing physical activity and improving nutrition."